Estimating dead organic matter carbon dynamics of an intact mixed dipterocarp forest in Brunei with a forest carbon model
Intact tropical forests contain substantial amount of carbon (C) and play an important role in global carbon cycles. Field measurement is needed to quantify dead organic matter (DOM) C dynamics in tropical forests while it requires much labor and cost. In contrast, forest carbon models can simulate C dynamics, overcoming the limitation of field measurement. In this study, we simulated the DOM C dynamics of an intact mixed dipterocarp forest at Kuala Belalong in Brunei, by using a forest carbon model. In order to estimate the annual changes in the C stocks of litter layer, dead root, coarse woody debris (CWD), and soils, a forest carbon model, KFSC model, was parameterized to the study site. In order to initialize the KFSC model, the C stocks in biomass, litter layer, CWD, and soils were measured in twenty seven 20 m x 20 m plots in 2014. The measured C stocks (Mg C ha-1) in litter layer, dead root, CWD, and soils were 3.2 ± 0.5, 4.0 ± 1.9, 32.5 ± 38.9, and 75.2 ± 9.2, respectively. The simulation results showed that the annual changes in the C stocks (Mg C ha‑1 yr-1) of litter layer, dead root, CWD, and soils were 2.7 ± 2.0, 1.4 ± 1.8, -1.5 ± 7.7, and 0.5 ± 1.8, respectively. The total DOM C stocks tended to increase at the rate of 3.3 ± 9.6 Mg C ha‑1 yr-1, but it exhibited the high variation. This might be attributed to the high variation of the annual changes in the CWD C stocks. Our results exhibited the applicability of forest carbon models to quantify DOM C dynamics in intact tropical rain forests.
This study was supported by Korea Ministry of Environment (2014001310008) and Korea Forest Service (S121314L130110).